Commit message: Fix crash in MatrixSolve when inputs have different batch dimensions.

Before, the process would crash or certain elements would be silently ignored. Now an InvalidArgument is raised.

PiperOrigin-RevId: 384844020
Change-Id: Iba44417e383bdd0e1abc4012bfca83b2377dd335
CVE: CVE-2021-41206
CWE: CWE-354
Vulnerability description: TensorFlow is an open source platform for machine learning. In affected versions several TensorFlow operations are missing validation for the shapes of the tensor arguments involved in the call. Depending on the API, this can result in undefined behavior and segfault or `CHECK`-fail related crashes but in some scenarios writes and reads from heap populated arrays are also possible. We have discovered these issues internally via tooling while working on improving/testing GPU op determinism. As such, we don't have reproducers and there will be multiple fixes for these issues. These fixes will be included in TensorFlow 2.7.0. We will also cherrypick these commits on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, as these are also affected and still in supported range.

Project: tensorflow
File: matrix_solve_op.cc

  void ComputeAsync(OpKernelContext* context, DoneCallback done) final {
    const Tensor& input = context->input(0);
    const Tensor& rhs = context->input(1);
    const int ndims = input.dims();
    const int64 n = input.dim_size(ndims - 1);
    const int64 nrhs = rhs.dim_size(ndims - 1);
    // Validate inputs.
    OP_REQUIRES_ASYNC(
        context, ndims >= 2,
        errors::InvalidArgument("Input must have rank >= 2, got ", ndims),
        done);
    OP_REQUIRES_ASYNC(context, rhs.dims() == ndims,
                      errors::InvalidArgument(
                          "Input and right-hand side must have same rank, got ",
                          ndims, " != ", rhs.dims()),
                      done);
    OP_REQUIRES_ASYNC(
        context, input.dim_size(ndims - 2) == n,
        errors::InvalidArgument("Input matrices must be squares, got",
                                input.dim_size(ndims - 2), " != ", n),
        done);
    OP_REQUIRES_ASYNC(context, rhs.dim_size(ndims - 2) == n,
                      errors::InvalidArgument(
                          "Input matrix and right-hand side must have the "
                          "same number of rows, got",
                          n, " != ", rhs.dim_size(ndims - 2)),
                      done);

    // Allocate output.
    Tensor* output;
    OP_REQUIRES_OK_ASYNC(
        context,
        context->forward_input_or_allocate_output({1}, 0, rhs.shape(), &output),
        done);

    // To be consistent with the MatrixInverse op, we define the solution for
    // an empty set of equations as the empty matrix.
    if (input.NumElements() == 0 || rhs.NumElements() == 0) {
      done();
      return;
    }

    // TODO(rmlarsen): Convert to std::make_unique when available.
    std::unique_ptr<CudaSolver> solver(new CudaSolver(context));

    // Make a copy of the input for the factorization step, or, if adjoint_ is
    // false, try to reuse the input buffer if this op owns it exclusively.
    Tensor input_copy;
    const GPUDevice& device = context->eigen_device<GPUDevice>();
    if (adjoint_) {
      // For the adjoint case, it is simpler to always make a transposed copy up
      // front.
      OP_REQUIRES_OK_ASYNC(
          context,
          solver->allocate_scoped_tensor(DataTypeToEnum<Scalar>::value,
                                         input.shape(), &input_copy),
          done);
      OP_REQUIRES_OK_ASYNC(context,
                           DoMatrixTranspose(device, input, &input_copy), done);
    } else {
      OP_REQUIRES_OK_ASYNC(
          context,
          solver->forward_input_or_allocate_scoped_tensor(
              {0}, DataTypeToEnum<Scalar>::value, input.shape(), &input_copy),
          done);
      if (!input.SharesBufferWith(input_copy)) {
        device.memcpy(input_copy.flat<Scalar>().data(),
                      input.flat<Scalar>().data(),
                      input.NumElements() * sizeof(Scalar));
      }
    }
    auto input_copy_reshaped = input_copy.template flat_inner_dims<Scalar, 3>();
    const int64 batch_size = input_copy_reshaped.dimension(0);

    // Allocate pivots on the device.
    Tensor pivots;
    OP_REQUIRES_OK_ASYNC(
        context,
        solver->allocate_scoped_tensor(DataTypeToEnum<int>::value,
                                       TensorShape{batch_size, n}, &pivots),
        done);
    auto pivots_mat = pivots.template matrix<int>();

    // 1. Compute the partially pivoted LU factorization(s) of the
    // matrix/matrices.
    std::vector<DeviceLapackInfo> dev_info;
    auto input_copy_ptrs = solver->GetScratchSpace<uint8>(
        sizeof(Scalar*) * batch_size, "input_copt_ptrs",
        /* on_host */ true);
    const int kMaxMatrixSizeToBatchSizeRatio = 128;
    const bool use_batched_solver =
        n <= kMaxMatrixSizeToBatchSizeRatio * batch_size;
    if (use_batched_solver) {
      // For small matrices or large batch sizes, we use the batched interface
      // from cuBlas.
      const Scalar** input_copy_ptrs_base =
          reinterpret_cast<const Scalar**>(input_copy_ptrs.mutable_data());
      for (int batch = 0; batch < batch_size; ++batch) {
        input_copy_ptrs_base[batch] = &input_copy_reshaped(batch, 0, 0);
      }
      dev_info.push_back(
          solver->GetDeviceLapackInfo(batch_size, "getrfBatched"));
      OP_REQUIRES_OK_ASYNC(
          context,
          solver->GetrfBatched(n, input_copy_ptrs_base, n, pivots_mat.data(),
                               &dev_info.back(), batch_size),
          done);
    } else {
      // For small batch sizes or large matrices, we use the non-batched
      // interface from cuSolver, which is much faster for large matrices.
      dev_info.push_back(solver->GetDeviceLapackInfo(batch_size, "getrf"));
      for (int batch = 0; batch < batch_size; ++batch) {
        OP_REQUIRES_OK_ASYNC(
            context,
            solver->Getrf(n, n, &input_copy_reshaped(batch, 0, 0), n,
                          &pivots_mat(batch, 0), &dev_info.back()(batch)),
            done);
      }
    }

    // 2. Make a transposed copy of the right-hand sides. This is necessary
    // because cuBLAS assumes column-major storage while TensorFlow TF uses
    // row-major.
    TensorShape transposed_rhs_shape(rhs.shape());
    transposed_rhs_shape.RemoveLastDims(2);
    transposed_rhs_shape.AddDim(nrhs);
    transposed_rhs_shape.AddDim(n);
    Tensor transposed_rhs;
    OP_REQUIRES_OK_ASYNC(
        context,
        solver->allocate_scoped_tensor(DataTypeToEnum<Scalar>::value,
                                       transposed_rhs_shape, &transposed_rhs),
        done);
    if (nrhs > 1) {
      OP_REQUIRES_OK_ASYNC(
          context, DoMatrixTranspose(device, rhs, &transposed_rhs), done);
    } else {
      device.memcpy(transposed_rhs.flat<Scalar>().data(),
                    rhs.flat<Scalar>().data(),
                    rhs.NumElements() * sizeof(Scalar));
    }

    // 3. Solve op(A) X = B (in column major form).
    // We use a trick here: If adjoint_ is true, we converted A to column major
    // form above. If adjoint is false then I leave A in row-major form and use
    // trans_a = CUBLAS_OP_T to effectively transform it to column-major on the
    // fly. (This means that we actually use the LU-factorization of A^T in that
    // case, but that is equally good for solving AX=B). This way we save an
    // explicit transpose in the more common case of adjoint_ == false.
    auto input_copy_ptr_array = solver->GetScratchSpace<uint8>(
        sizeof(Scalar*) * batch_size, "input_copy_ptr_array",
        /* on_host */ true);
    auto transposed_rhs_ptr_array = solver->GetScratchSpace<uint8>(
        sizeof(Scalar*) * batch_size, "transposed_rhs_ptr_array",
        /* on_host */ true);
    auto transposed_rhs_reshaped =
        transposed_rhs.template flat_inner_dims<Scalar, 3>();
    if (use_batched_solver) {
      const Scalar** input_copy_ptrs_base =
          reinterpret_cast<const Scalar**>(input_copy_ptr_array.mutable_data());
      const Scalar** transposed_rhs_ptrs_base =
          reinterpret_cast<const Scalar**>(
              transposed_rhs_ptr_array.mutable_data());
      for (int batch = 0; batch < batch_size; ++batch) {
        input_copy_ptrs_base[batch] = &input_copy_reshaped(batch, 0, 0);
        transposed_rhs_ptrs_base[batch] = &transposed_rhs_reshaped(batch, 0, 0);
      }
      int host_info = 0;
      OP_REQUIRES_OK_ASYNC(
          context,
          solver->GetrsBatched(adjoint_ ? CUBLAS_OP_C : CUBLAS_OP_T, n, nrhs,
                               input_copy_ptrs_base, n, pivots_mat.data(),
                               transposed_rhs_ptrs_base, n, &host_info,
                               batch_size),
          done);
      OP_REQUIRES_ASYNC(
          context, host_info == 0,
          errors::InvalidArgument("The ", -host_info,
                                  "'th argument to cublas*getrsBatched had "
                                  "an illegal value."),
          done);
    } else {
      dev_info.push_back(solver->GetDeviceLapackInfo(batch_size, "getrs"));
      for (int batch = 0; batch < batch_size; ++batch) {
        OP_REQUIRES_OK_ASYNC(
            context,
            solver->Getrs(adjoint_ ? CUBLAS_OP_C : CUBLAS_OP_T, n, nrhs,
                          &input_copy_reshaped(batch, 0, 0), n,
                          &pivots_mat(batch, 0),
                          &transposed_rhs_reshaped(batch, 0, 0), n,
                          &dev_info.back()(batch)),
            done);
      }
    }

    // 4. Transpose X to get the final result in row-major form.
    if (nrhs > 1) {
      OP_REQUIRES_OK_ASYNC(
          context, DoMatrixTranspose(device, transposed_rhs, output), done);
    } else {
      device.memcpy(output->flat<Scalar>().data(),
                    transposed_rhs.flat<Scalar>().data(),
                    transposed_rhs.NumElements() * sizeof(Scalar));
    }

    // Callback for checking info after kernels finish. Also capture the
    // temporary Tensors/ScratchSpace so they don't get deallocated before the
    // kernels run. TODO(rmlarsen): Use move capture once C++14 becomes
    // available.
    auto info_checker = [context, done, dev_info](
                            const Status& status,
                            const std::vector<HostLapackInfo>& host_infos) {
      if (!status.ok() && errors::IsInvalidArgument(status) &&
          !host_infos.empty()) {
        for (int i = 0; i < host_infos[0].size(); ++i) {
          // Match the CPU error message for singular matrices. Otherwise
          // just print the original error message from the status below.
          OP_REQUIRES_ASYNC(context, host_infos[0].data()[i] <= 0,
                            errors::InvalidArgument(kErrMsg), done);
        }
      }
      OP_REQUIRES_OK_ASYNC(context, status, done);
      done();
    };
    CudaSolver::CheckLapackInfoAndDeleteSolverAsync(std::move(solver), dev_info,
                                                    std::move(info_checker));
  }